Knee replacement implants are artificial devices that are used to replace a damaged knee or a part of a knee thereof.
A damaged knee joint will contain a combination of bone structure and multiple soft tissue groupings and depending upon where the knee damage arrived from, whether rheumatoid arthritis, osteoarthritis and/or traumatic injury means that every knee replacement or partial knee replacement will either be, if not substantially, at least subtly different albeit ultimately the artificial implants used in the knee replacement will be for the most part of standard sizes.
While an objective of any knee replacement utilising implants would look for an exact reproduction of the structure and operation of a normal healthy knee, as introduced above such a scenario would be very difficult to achieve given the potential differing degrees in the severity of damage to the knee joint and the differences of an individual's bone structures to another.
During surgery, an orthopaedic surgeon when replacing a damaged knee with replacement implants will be required to prepare those bone structures involved in the knee joint to accept the artificial implant including the distal end of the femur, the proximal surface of the tibia and the patella.
This invention focuses on the lower half of the knee hinge joint associated with the proximal surface of the tibia. The correct positioning of the tibial component upon the proximal surface of the tibia assists in providing the best long-term stability of the prosthetic knee joint.
It is recognised that the level of bone resection of the proximal surface of the tibia assists in correct alignment of the tibial component of the prosthetic knee joint to establish an appropriate gap between both the tibial component and the femoral component to ensure stable and secure balanced movement of the knee joint, not only at flexion and extension but at also through out mid-flexion as the knee completes its angular movement between flexion and extension.
Accordingly it is an object of this invention to provide an arrangement and a method such that the proximal surface of the tibia level or profiling of final bone resection of the surface of the tibia provides for optimum tibial component positioning in the total knee arthroplasty such that there is a stable and balanced movement between the tibial component and the femoral component in the prosthetic knee joint throughout the complete arc of motion of the knee from extension, mid-flexion through to flexion.
Further objects and advantages of the invention will become apparent from a complete reading of this specification.